Dust-cap.



H. P. KRAFT. DUST CAP:

APPLICATION {ILED JUNE 30.1917- Pa-tented Feb. 25, 1919.

INVENTOR HENRY r. KRAFT, or mnenwoon, NEW JERSEY.

I DUST-CAP.

Specification of Letters Patent. Patented 25', 1919.

Application filed June 30, 1917.- Serial No. 178,026.

To all whom it may concern:

Be it known that I, HENRY P. KRAr'r, a citizen-of the United States of America, residing inR-idgewood, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements 1n Dust-Caps, of which the following is a specification. v

This invention relates a to dust caps for valves orthe like, and aims to provide certain improvements therein.

The invention .in its preferred form is particularly directed to dust caps of the type set forth in a previous application filed by me, Serial No. 169,384. In the construction shown in said application there is provided a cap section and a sleeve section, the cap section being adapted to screw a certain d1stance upon the valve shell and the sleeve section telescoping with the cap section and being adjustable to slide alon the valve casing to different positions wit A relation to the cap section, whereby valves of different degrees of projection may be suitably housed or inclosed by the cap.

The present invention is directed to a cap of this type in which the cost of construction is reduced, the cap section being constructed of thin sheet metal. I

Referring to the drawings which illustrate one form of the invention,-

Figure 1 is a diam'etrica-l section of my im proved cap, illustrated as applied to a valve casing, the latter being shown in elevation.

Fig. 2 is an elevation of the cap, partly broken away, and shown as applied to a valve casing of greater length than that in Fi 1.

Fig. 3 is a bottom view of the sleeve sec tion.

Referring to the drawing, an ordinary valve casing and B the dust cap as a wholev The dust cap is shown as comprising a cap section C which is preferably closed at its bottom end and which is adapted to engage the threads of the valve casing, and a sleeve section D which telescopes upon the cap section and which is provided with spring arms E E adapted to frictionally embrace the valve casing and hold the sleeve section in any position to which it may be adjusted. When the cap is used on a short valve, as shown in Fig. 1, the cap and sleeve sections are nearly collapsed, and when used upon a long valve, as shown in Fig. 2, they are almost fully extended.

let A indicate cap may be quickly attached and detached, .7

it is given but a limited engagement with the valve casing, near the inner end of the latter, as shown at F; In the construction shown the thread G of the cap section is located intermediate of its ends, the open end H being of a diameter which is greater than that of the valve casing. It is quite desirable that there shall he means for limiting the onward screwing of the cap .section not only in order to provide for a quick attachment and detachment, but also to avoid contact of the closed end of the sleeve section with the valve cap I, for instance. In the simpler form of stop shown in the previous application the screw-thread G is terminated to leave the metal ahead of it of such diameter as to form the stop. This necessitates the use of a fairly heavy metal for the cap section which increases its cost without the corresponding advantage. According to the present invention I construct the cap section of drawn metal which is of light gage, the

to slide over the screw-threaded casing. A portion J of the cap sectiomis made of less diameter interiorly and exteriorly than the portion H. Preferably the portion J comprises a short section intermediate of the two ends which is bent or spun inwardly to decrease its diameter, so that it may be threaded to receive the valve shell. A stop ofsome kind is preferably used and the simplest form is that shown wherein'the thread G instead of passing the whole length of the constriction J is terminated before it reaches the end thereof. The outer end of the cap is best left open portion H being of suflicient diameter I 1. A dust cap formed of drawn metal and 11 0 having an open end adapted to slip over a valve, and a portion above the lower end constricted internally and externally to a diameter less than that of either end, and threaded internally.

2. A dust cap formed of drawn metal and having an open end adapted to slip over a valve, and a portion above the lower end constricted internally and externally to a diameter less than that of either end, and threaded internally, and a stop limiting the onward movement of said cap. 4

3. A dust capformed of drawn metal and being generally of a diameter to slip over a valve casing and having a constricted portion partially threaded, said constricted portion being of less diameter than the portions on either side of it.-

4. A dust cap formed of drawn' metal, having an open end adapted to slip over a valve, and a portion above the lower end constricted internally and externally to a diame- 'ter less than that of either end, and threaded internally, and a telescopic sleeve on the exterior of said dust cap, the outer end of said' sleeve having an internal diameter greatervthan that of said constricted portion and substantially that of the cap between said constricted portion and the closed end of the cap, so it may slide along the latter.

5. A dust cap formed of drawn metal, having an open end adapted to slip over a valve,

and a portion above the lower end constricted internally and externally to a diameter less than that of either end, and threaded internally, and a stop limitin the onward -movement of said cap, and a te escopic sleeve on the exterior of said dust cap, the outer end ing an open end adapted to slip over a valve,

and a portion above the lower end constricted internally and externaly to a diameter less than that of either end, and threaded internally for a part of its length, whereby the unthreaded portion constitutes a stop, said constricted portion being of less diame ter than the portions" on either side of it, and a telescopic sleeve on the exterior of said dust cap, the outer end of said sleeve having an internal diameter greater than that of said constricted portion and substantially that of the cap between said constricted portion and the closed end of the cap, so it may slide along the latter.

In witness whereof, I have hereunto signed my name.

HENRY P. KRAFT. 

